Douai is a city in the Nord département in northern France. It is a sub-prefecture of the department. Located on the river Scarpe some 40 ki…Douai is a city in the Nord département in northern France. It is a sub-prefecture of the department. Located on the river Scarpe some 40 kilometres from Lille and 25 km from Arras, Douai is home to one of the region's most impressive belfries.